An observational study of fixed dose combination fluticasone propionate/salmeterol or fluticasone propionate alone on asthma-related outcomes

ABSTRACT

Objective: To identify the relationship between resource utilization and treatment of asthma in subjects who were first time users of controller therapies, either fluticasone propionate (FP) and salmeterol delivered in a single Diskus device (FSC) or FP monotherapy.

Methods: A retrospective, observational cohort analysis evaluated pharmacy and medical claims from subjects from a commercial managed-care database, which is similar in makeup to the US privately insured population, with a diagnosis of asthma and ≥1 prescription for FSC or FP dispensed from 1/1/2001 to 4/30/2005. Outcomes of interest were asthma-related emergency department (ED) visits, inpatient (IP) visits, and a combined outcome (IP or ED visits). Predicted rates of asthma-related and all-cause intubations were also reported for each cohort. Multivariate analysis of events was conducted using logistic regression and Cox proportional hazard regression. All outcomes were adjusted for differences in baseline characteristics.

Results: There were 58 270 subjects identified (FSC, n = 42 466; FP, n = 15 804). Mean age was 37.65 years and 35.75% was female. The use of FSC was associated with lower risk of having an asthma-related ED visit (adjusted OR 0.79; 95% CI, 0.72–0.87) and an asthma-related ED/IP visit (OR 0.80; 95% CI, 0.73–0.88). Asthma-related ED and ED/IP rates were also significantly lower for FSC than for FP. There were no differences observed in post-index asthma-related intubations rates.

Conclusion: In this observational study using a large managed-care database, subjects treated with FSC were at significantly less risk for developing serious asthma exacerbations and had lower resource utilization than a cohort of subjects treated with FP. This is clinically meaningful despite the inherent limitations of these types of observational studies.

Key words: :

• Asthma
• Emergency medical services
• Fluticasone propionate
• Fluticasone propionate-salmeterol combination
• Hospitalization
• Salmeterol
• Utilization

Acknowledgements

Declaration of interest: The study was funded by GlaxoSmithKline. A.R. and G.G.R. work for i3Innovus which received grant support from GlaxoSmithKline for this study. R.H.S. and D.A.S. are employees of GlaxoSmithKline. A.F. was involved with the design, analysis and writing of the study but did not receive any money for work on this project. However, she has served as a consultant to GlaxoSmithKline, Merck, Novartis and Sepracor for epidemiologic studies; received unrestricted research support from GlaxoSmithKline, Merck and Boehringer Ingelheim; served on an advisory board and has been a member of a speakers’ bureau for GSK and Merck; and has served as a member of the DSMB for an industry-sponsored clinical trial (Sepracor). The authors thank Cynthia Toso, PharmD, an independent writer, for assistance in preparing the manuscript.

Notes

* Data in this paper were presented at the Annual Meeting of the American College of Allergy, Asthma, and Immunology, November 9–15, 2006, Philadelphia, PA, USA